Most people have probably seen the recent news that Monsanto has been ordered to pay $289 million following the ruling by a California jury that Monsanto’s glyphosate (a.k.a. Roundup) is dangerous and likely contributed to Dewayne Johnson’s cancer. I could write many lengthy posts about why that ruling is wrong. I could talk about the numerous scientific studies that failed to find evidence that glyphosate causes cancer (e.g., this large, long-term cohort study with over 50,000 participants that wasn’t funded by Monsanto and failed to find an association between glyphosate use and cancer among farmers [Andreotti et al. 2017]). I could talk about the well-established fact that the toxicity of glyphosate is quite low. I could talk about the fact that multiple well-respected scientific bodies have examined the evidence and concluded that it does not suggest that glyphosate causes cancer. I could also talk about how the one dissenting scientific report (i.e., WHO’s IARC report) cherry-picked their evidence and reached a conclusion that has been widely criticized by the scientific community. Plenty of other pages have, however, already done all of those things, so I won’t spend more time on them here. Rather, I want to discuss why trials like this one are inherently problematic. Citing court rulings is an extremely common tactic among science deniers (anti-vaccers do it all the time), but it is not a logically valid tactic because courts don’t determine what is and is not a scientific fact.

The first major problem is simply that juries don’t consist of experts in the relevant scientific field. As I’ve talked about before, science is complicated. It takes years of carefully training, study, and hands-on experience to learn everything that you need to know to be able to properly evaluate scientific evidence. The notion that an untrained jury is going to master that over the course of a trail is absurd. Further, it is especially ridiculous when you consider that courtroom conditions inherently involve two opposing sides arguing as if they have equivalent merit. To put that another way, it is extremely easy to cherry-pick evidence to make it look like the science isn’t settled on an issue or, worse yet, like the scientific consensus is the opposite of what it actually is, and in a courtroom, a lawyer will do precisely that. They are obligated to argue in favor of a given position, regardless of whether that position is actually supported by the evidence.

Let me try an example. Imagine that there is some issue with your heart that you want diagnosed, and someone suggested to you that it might be because a particular aspect of your diet (i.e., you eat X, and they think X is bad for your heart). So, you take two approaches to figuring out whether your diet is the cause. In the first approach, you get multiple respected scientific organizations to examine the scientific evidence that X can lead to heart problems. These bodies of highly trained and experienced experts spend months or even years systematically examining the studies on this topic. The look at all the evidence that they can get and, ultimately, they conclude that there is no compelling evidence for X contributing to heart problems.

For the second approach, you construct a jury using the same criteria as in a court, then you get two lawyers to debate the issue as in a courtroom. One of them tries to convince the jury that X does cause heart problems, and the other tries to convince the jury that X does not cause heart problems. Rather than systematically examining all of the evidence, both lawyers cherry-pick evidence that supports their position, attempt to play on the jury’s emotions, bring in cherry-picked “expert” witnesses, etc. At the end of the trial, the jury concludes that X does cause heart problems (which is the opposite of what the scientific committees found).

Which conclusion seems more reliable to you? The one that was arrived at by experts spending months carefully and systematically examining all of the available evidence, or the one that was arrived at by non-experts basing a decision on a comparison of two extremely biased representations of the evidence? I think that the answer to that is pretty obvious.

To be clear here, I’m not saying that scientists are infallible or that the conclusions of scientific organizations are definitive statements of reality. That would be an appeal to authority fallacy. Rather, my point is that the courtroom system is fundamentally flawed and unreliable for determining scientific facts. The fact that a jury decided that X causes Y is completely and 100% irrelevant in any scientific debate. It has no bearing on reality, and you would be crazy to trust it instead of relying on numerous high-quality studies and reviews and meta-analyses of those studies that were systematically assembled by teams of experts. Whether or not something is a scientific fact has to be determined by actual research, and a jury’s opinion about that research is irrelevant.

54 Responses to Courts don’t determine scientific facts

I do agree with you that courts are not good forums for scientific fact finding. Completely. I just want to add – not as a disagreement, but as agreement – that there is a belief behind our adversarial system, and one version of it – this is more complex – is that the best way to discover the truth is to let two interested parties put their best case forward, on the assumption that they will do what they can to discover the facts and present them. That is flawed in all kinds of ways, and not just in science, but it’s the reasoning behind our system. It’s not just that it almost forces the two sides to cherry pick: it’s that it’s vulnerable to acting ability, to emotional manipulation, to memory and perception flaws of the lay people, and to resource differences between the parties.

It’s a problematic system, as a way to find the truth, and not just in science.

That is equally true of juries finding on negligence in a slip and fall case or anything else including criminal cases. It is just not a good system. The alternative would be institutionalized panels of experts to resolve disputes. Which is immediately corrupted by putting such absolute power in limited hands, and that’s even worse. Especially for dissenting voices.

Good lawyers should be able to win on good facts. If they don’t, that’s a problem with the lawyers. They should also be able to select relatively intelligent jurors. Alternatively, they should try to avoid jury trials – not that judges are scientific experts, but they can handle patent & environmental cases decently. Better still, lock consumers into commercial arbitration where you can get a panel with the skill needed to evaluate scientific claims.

Montsanto should do okay on appeal if they don’t just settle for a couple mil first.

I am a retired federal and state trial attorney who specialized in complex scientific technical litigation. I did not litigate pesticide cases — I have been diagnosed with Stage IV Non Hodgkin’s Lymphoma. I probably did not get my NHL from Roundup; there are many causes of this blood cancer, but epidemiological studies show a high incidence among those who work with pesticides.

The author is correct that jury trials should not be relied upon to determine scientific facts.
The adversarial legal system is not designed to function with scientific precision. Indeed, under California law a plaintiff may recover damages if they can show that a breach of the duty of care was only a substantial factor in causing the damages. The alleged negligent act does not have to be proven to be the exclusive cause of the harm. Juries and lawyers ARE subjective and (“cherry pick”) choose to rely on some evidence. Don’t tell me that scientists don’t cherry pick evidence and choose what to emphasize in their papers.
So, should we rely on scientists and WAIT for decades, while they cannot agree about whether glyphosate is carcinogetic. Shouldn’t they at least warn us? (I remember when tobacco manufactures put warnings on cigarettes that say smoking might cause lung cancer, berating lawyers for lawsuits, while their chief scientists had internal memos revealing they were convinced smoking caused cancer.

The WHO made up of scientists says that glyphosate probably is carcinogenic. Can scientists assure people who are getting a certain kind of cancer from a suspicious chemical, that they have nothing to worry about. If scientists are willing to give this assurance they should disclose something:

In 2016,
A UN panel ruled that glyphosate was probably not carcinogenic to humans has now become embroiled in a bitter row about potential conflicts of interests. It has emerged that an institute co-run by the chairman of the UN’s joint meeting on pesticide residues (JMPR) received a six-figure donation from Monsanto, which uses the substance as a core ingredient in its bestselling Roundup weedkiller.

A separate report last year by the International Agency for Research on Cancer (IARC) – WHO’s cancer agency – which only considered publicly available studies, concluded that glyphosate was probably carcinogenic to humans. But WHO officials maintain there is no contradiction between the two papers, noting that IARC was identifying a potential hazard, whereas the JMPR was quantifying the associated risk.

They say lawyers talk out of both sides of their mouths: Ask a cancer patient whether scientists are talking out of both sides of their mouths when they say there is no contradiction between identifying a potential [cancer] hazard or just quantifying the “ASSOCIATED” risk.

Every item (except one) the WHO has studied gets the same verdict. Their analysis can and should be dismissed by all.

“The World Health Organization’s International Agency for Research on Cancer (IARC) began categorizing substances based on their likelihood of causing cancer in 1970. Since then, they’ve categorized 989 different substances – and only one has made it into Group 4, the “probably not carcinogenic to humans” category.”

The point about scientists cherry-picking is an important one, because good reviews and meta-analyses shouldn’t. When looking at a review, you need to see if it was “systematic.” This means that when collecting the papers to include in the review, the scientists used a pre-defined set of search terms/criteria and then included all of the studies that met those criteria, regardless of the conclusion of those studies (the criteria, of course, have to be valid, unbiased criteria, or else it is still a form of cherry-picking). This avoids cherry-picking.

The problem with the WHO report you are citing is precisely that they didn’t do this. They used criteria that deliberately excluded numerous studies that would have changed their conclusion. Every other major assessment (which did not use their biased criteria) has found that there is no compelling evidence that glyphosate causes cancer. The links in the first paragraph of this post talk more about both the WHO report and the other reports.

You are mixing up “insecticides” and “pesticides”. Anything that interferes with a crop is a pest, including weeds, so yes by definition Roundup is a pesticide. Or I guess you could use a nuisancecide.

From WHO, “Pesticides are chemical compounds that are used to kill pests, including insects, rodents, fungi and unwanted plants (weeds)”

Herbicides are pesticides that kill plants. Insecticides are pesticides that kill insects. Fungicides are pesticides that kill fungi. etc. To put that another way, all herbicides are pesticides, but not all pesticides are herbicides.

No, Phil, asking cancer patients about their risk factors is just about as worthless as asking an anti-vaxxer to credibly “explain” their kid’s unrelated autism. And your claim that epi studies show a high incidence is bogus (you didn’t even post such “studies”). Moreover, duhhhh, don’t you think that farmers who work with glyphosate every day would be shown to have higher incidences? They don’t.
Phil, as an attorney and especially one who has ostensibly worked in science, you of all people should know that anecdotes are not data. You’re going off on a tangent with cherry-picked claims, exactly the logical (and legal) fallacies this article has pointed out.
But I’m sure you would love to get into the thick battle of these lawsuits with your cherry-picked claims, Phil.

” but epidemiological studies show a high incidence among those who work with pesticides.”

Anyone who works with industrial, laboratory, or agrichemical preparations show higher risks for cancers and have shorter lifespans. But please don’t conflate that with glyphosate (Roundup), nor previous generations and current generations. People working with agrichemicals won’t just work with glyphosate, they will work with a huge range of chemicals, are more likely to work outdoors, are more likely to have higher exposures to other carcinogens, etc. So a farmer could use glyphosate but also use something actually dangerous and a known carcinogen. It should also be noted that chemical safety and handling practices have changed a lot in the last 30 years, so “risk” is much better managed now.

I think there is a difference between establishing something based on science vs covering your own butt in the face of litigation if you are wrong. So the WHO decision strikes me as a political decision rather than a factual one. I don’t understand why people are not suing because warning labels are not put on sawdust, which is a KNOWN carcinogen. I am NOT defending Monsanto. I think their abuse of corporate “personhood” and bad business practices are what should be targeted, not a product that has been extensively tested. When we do science with an a priori confirmation bias, science becomes a swamp.

This case has a lot of problems and this amount of damages will be either reversed or lowered on appeal. This is clearly a case of shopping for a favorable jury – San Francisco, no less, and with a celebrity enviro lawyer on the plaintiff team, Robert Kennedy, Jr. . Here are excerpts from the actual instructions on a Round-Up label: “WARNING
POISON (even has a skull and crossbones illustration)
EYE AND SKIN IRRITANT – PRECAUTIONS
KEEP OUT OF REACH OF CHILDREN.
HARMFUL IF SWALLOWED.
HARMFUL IF INHALED.
CAUSES EYE AND SKIN IRRITATION.
Avoid contact with eyes, skin or clothing.
Avoid inhaling spray mist.
Wear a long-sleeved shirt and long pants during mixing, loading, application, clean-up
and repair. In addition, wear goggles or a face shield and chemical-resistant gloves during
mixing and loading, clean-up and repair.
The restricted entry interval is 12 hours after application for all agricultural uses.” The plaintiff never wore protective clothing, admitted to spraying on a windy day and being exposed, and even being completely soaked in the chemical when a tube broke on his sprayer. Most idiots using herbicides and pesticides do not wear protective clothing or read the instructions for use. Furthermore, there are over 90 types of non Hodgkin’s lymphomas and if anyone knew what “caused” them, it would be worth a Nobel prize. There is a possibility that the plaintiff’s extreme exposure may have “contributed” to his NHL, nevertheless, if you are stupid enough to never wear protective gear around poisonous chemicals then the company is hardly responsible.

Correct. It has been shown, time and time again, that glyphosate is safe “when used as directed.” Yet the opponents say stupid stuff like “Fine; if it’s so safe, drink it then,” as if that admonition has any relevance to science and safety of glyphosate. There’s no explaining stupid.

A scientist who advised a United Nations agency to classify the world’s most widely used weedkiller as carcinogenic received $160,000 (£121,500) from law firms bringing claims by cancer victims against the manufacturer.

Christopher Portier advised the International Agency for Research on Cancer (IARC), part of the World Health Organisation, which concluded in March 2015 that glyphosate was a “probable human carcinogen”.

He did not declare his links to the law firms in a letter to the European Commission urging it to accept the IARC classification.

The alternative is to use a term that panders to them but creates the false appearance of rationality. For example, the term “climate skeptics” is misleading. Skepticism is demanding good evidence before reaching a conclusion. Denial, is ignoring a massive body of evidence that you don’t like (which is what climate change deniers, anti-vaccers, anti-GMO activists, creationists, etc. are doing). So I will continue to use the term “science deniers” because it is accurate. People who choose to willfully ignore massive bodies of evidence are, by definition, denying science, and I’m not going to sugarcoat that.

BTW, if you want discourse, don’t do your best to shut people down before they can present information. Calling people derogatory names isn’t accurate. It is shameful. In the long run, I’m sure taking the high road is more important.

Anti-vaccers are a logical extension of very real problems with _some_ vaccines, most notably, the Rubella vaccine, which doesn’t play well with others. The MMR, one of the most widely used vaccines in the world, increases the rate of febrile seizures and encephalitis by a small margin. The margin was much larger when the MMR was co-administered with the polio vaccine, so is not recommended by the CDC.

The larger question, is why are we using the MMR at all? There is no theory of immunology that says taking on 3 weakened viruses at the same time is a good idea. It’s just a cost and time efficient one, with calculated increases in risk. If you’re a parent in that margin though, you’re likely to become anti-vax, because no one is going to actually explain to you honestly that your child was just a victim of economic efficiency and risk uncertainty… because that’s not very comforting or humane.

Similarly, in the U.S., most roads and rooftops are black. How hard would it be to make them at lower altitudes solar panels instead, so we turn some of that heat back into usable power, and reverse some entropy? At higher altitudes, just paint them white and reflect the light out of the atmosphere, leaving less total heat within the planetary climate?

Our failure to even try fuels disbelief – if climate scientists are so certain about global warming, why isn’t anyone doing anything about emission reduction, or heat conversion as means to cut down on it? If climate change is real, why aren’t scientists making solutions other than demanding sacrifice from the plebes?

This is a myopic interpretation, but has a kernel of truth — is it really so hard to grow grapes? They provide shade, so your house warms up less, and less HVAC is used, so less power is used, less emissions are made. Is it so hard to paint roads and roofs white at high altitudes, to reflect back the radiation heat from sunlight?

The studies are divided the closer to sea level you get, because it means the light travels through the atmosphere twice if reflected at low altitudes, through the thickest part of the atmosphere, which could result in null gain with some theories (I don’t think it correct, reflecting away, even going through atmosphere twice, leaves less total heat behind, as reflection will result in a measurable amount leaving the earth’s atmosphere, while absorption results in 0 leaving the planet, but I readily admit there’s nothing backing this speculation up. Just seems common sense from total planetary input and output perspective), but regardless of white paint, what’s clear is that solar paneling at any altitude absorbs the heat, and converts some back into usable energy, yet isn’t really being done.

As for glyphosate, the problem isn’t glyphosate in isolation, the problem is that RoundUp has other ingredients, and synergy is a very real thing. So, Monsanto will endlessly tout their glyphosate isolation studies, but unless people use glyphosate in isolation, it’s begging the question in regards to the safety of RoundUp, due to RoundUp being primarily, but not entirely glyphosate. There is evidence to suggest that RoundUp, not glyphosate by itself, is correlated with increased incidents of Hodgkin’s Lymphoma. Correlation, as we all know, is not causation.

I would argue that RoundUp doesn’t cause HL, but instead is a contributing and possibly triggering factor, so when combined with other triggering factors, does cause HL to become more likely to occur. Migraines are rarely caused by stress alone, usually, they’re a combination of somatic pain somewhere in the body, negative stress factors, emotional difficulties, and maybe another 3 factors (like bright lighting).

Point being, if we actually got precise in our analysis, but simple in our communicating what’s happening, instead of using jargon, sophistry, and pedantry, we’d be fuel less populist rage, which tends to go ignorantly forth with thoughtless autocratic solutions. People don’t like being lied to, and people don’t like their lives being valuated without their consent… and here we are.

Some contributors have pointed out that I used the term pesticides instead of herbicides. in my post commenting on the article which aptly pointed out that ‘courts don’t determine scientific facts’ in connection with the Roundup litigation.

Note, re-read my initial post, the only reason I used the term “pesticides,” is to distinguish my tech/sci litigation experience from that litigation involving pesticides, herbicides and fungicides in the agricultural use of chemicals. I was not using that word to classify Glyphosate. More to the point, I am aware of the scientific suspicion of these exogenic factors, as suspicious causes of non-Hodgkins Lymphoma. Indeed, there are numerous scientific peer reviewed epidemiological journal articles, noting a particularly high incidence of non-Hodgkin’s lymphoma patients worldwide who were exposed to such chemicals in agricultural settings.

So, back to the main issue: Do Courts determine scientific facts? — of course not.
Do lawyers on both side cherry pick facts – of course; but those of us who are not classified as scientists, would note that researchers select investigation protocols and cull out useful findings to support their papers, that is why we are bombarded with news of the latest study that purportedly debunks the findings of a previous study in almost every field of science. Commentators have pointed out that good scientists structure their research to avoid cherry picking, but there is rampant subjectivity in scientific research and all human endeavors. Let’s not discount the influence of money in support of causes, not only from lawyers on one side or the other, but also from other entities that influence the process.

My bottom line is, if there is a reasonable suspicion that the agricultural uses of chemicals is causing or contributing to non-Hodgkin’s Lymphoma, should those diagnosed with non-hodgkin’s lymphoma (most subtypes of advanced Non-Hodgkin’s Lymphoma are NOT CURABLE), wait decades for scientists to come to an agreement that they have determined the facts?

OR, can they go to court to allow both sides to present evidence on the issues. In U.S. Civil litigation, liability is determined by a preponderance of evidence and the judge determines what is admissible (including scientific evidence) by strict standards found in Evidence Codes which have been approved by our legislatures. Is there scientific precision (NO), is there subjectivity (Of course), but we have saying in the law, “where there is a wrong, there should be a remedy.” There will be no remedy via Science in our lifetime, for those of us with incurable cancers caused by chemicals manufactured by people.

“should those diagnosed with non-hodgkin’s lymphoma…wait decades for scientists to come to an agreement that they have determined the facts?”
The thing is that scientist have already come to an agreement. Sure, there are a few dissenting voices (as is true on literally every topic), but there is a very compelling body of evidence that glyphosate does not cause cancer, and, as explained previously, every large assessment of the literature has upheld that conclusion (with the exception of one expert assessment that is well-known to have cherry-picked data and had conflicts of interest).

That is one of the most specious anti-science posts I’ve read on this subject. No, Phil, a “reasonable suspician” most certainly does NOT justify a bad jury decision, FFS. If that were true, one could make an erroneous argument that anti-vaxxers and flat earthward have “reasonable suspicians.” That is not how science is done, and your facile explanation underscores the very point in this article.

Additionally, Phil, you started out saying you didn’t conclude that your own cancer was caused by pesticides, and you now conclude it was, in your statement “….for those of us with incurable cancers caused by chemicals manufactured by people.” (Um, as opposed to being manufactured by … wildebeests? Aliens? wtf?). Appears you have a mighty axe to grind, Phil, which does not lead to legal or cognitive bias-free opinion.

That’s not how science works. Saying, “these people live/work near glyphosate and have disorders X, Y, and Z, therefore glyphosate is the cause” is not different than an anti-vaccer blaming their child’s autism on a vaccine. That’s why we have to rely on actual studies about glyphosate toxicity. Indeed, your link includes statements like, “A recent investigation, as reported by Burn, estimated that 13.4 million Argentinians (one third of the country’s total population) have glyphosate-related disorders.” How on earth could he possibly have determined that? What were his criteria for deciding that something was a “glyphosate-related disorder.” Answer: anecdotes and preconceptions. Again, this is no different from anti-vaccers attributing seemingly all ailments to the category of “vaccine injury.”

The jury decided that the evidence showed that Monsanto acted with malice or oppression because they knew or should have known that it was carcinogenic and they should have warned users.

A lot of the evidence was involved with establishing that Monsanto knew it was a carcinogen. Have you reviewed this evidence, because if it does show that Monsanto deliberately covered up carcinogenicity then that changes the picture in relation to the scientific evidence in the public domain.

Jurys do not base their decisions on feelings, they are presented information, from experts in their fields and then decide.
The idea that the corporate giant Monsanto,”didn’t know” is Ludacris and irrelevant. Whether or not they knew it is carcinogenic matters not. It’s their product they are responsible. An example is if I hit someone with my car and kill them. I can’t just say, “I didn’t know he was crossing the street.” I would venture to guess Tina if it was.your husband or child I hit and killed, you would be very unlikely to let me off the hook for said incident.
Therefore I wonder why you or anyone else would not hold Monsanto responsible for their products? Why is it even a consideration? Is it just a smoke screen? A diversion?
What is… is. Of course chemicals used to KILL biological organisms have the potential to KILL all biological organisms. You don’t need to be a scientist to know that.
It’s simple logic. However, I can tell you this as a scientist, large amounts of many chemical substances deemed ok for human use can become carcinogenic or teratogenic.
Thus, I leave you to consider before standing behind claims of lack of accountability due to ignorance, to read the varying scientific resources available. Because posing an irrelevant statement such as, ignorance, does not remove accountability. They may very well be ignorant, however they should still be held accountable. It’s simple logic.

“It’s their product they are responsible. An example is if I hit someone with my car and kill them. I can’t just say, “I didn’t know he was crossing the street.”

A more apt analogy given your example would be if someone hit someone with their car, and the victim then sued Ford, saying, “It’s Ford’s product they are responsible.” The car itself is not dangerous if used as directed (for example, not running into people). The fault lies with the person using the product incorrectly.

In the same way, Monsanto’s product was scientifically shown to be safe if used as directed, but that doesn’t mean it’s Monsanto’s fault if someone bathes in it and then comes down with issues.

Given that numerous large, independent studies (like the one I cited) have found that glyphosate is not carcinogenic, I don’t really see how Monsanto could know that it is (i.e., if it was carcinogenic, then those large, independent studies should have found evidence that it was carcinogenic).

I have read through some of the court documents, but I have not read them all (honestly, I’m far more concerned about peer-reviewed studies than court documents). If there is a particular document that you think is damning, feel free to point it out.

Detecting small risks on rare conditions is of course going to be hard and some studies will not find an effect because they do not have enough data, although they are of course useful in narrowing down the likely risk, but I am sure that you will agree that proof as such does not exist is these contexts.

Even the study you quote concludes that there was “some evidence of increased risk of acute myeloid leukemia among the highest exposed group that requires confirmation.”

Skepticism means demanding good evidence before accepting a position. When large studies with the power to detect even small differences (such as the one I cited) failed to find evidence of causation, then you have to accept that result until such time as sufficiently large studies discredit it. Continuing to act that this is an unsolved problem despite studies like that is not skepticism, it’s denial.

If for glyphosate 1) other known carcinogens are not picked up in the AHS data, 2) the AHS study says more research is required to confirm the increased risk of acute myeloid leukemia, 3) there is other good evidence of increase in the micronuclei frequency, then there seems a perfectly good case for demanding better evidence before accepting your position that glyphosate is probably not a carcinogen.

For a “problem” to be “solved” requires proof, from what I can see the question is still very much open. I remain an unconvinced skeptic and not a denier.

First, regarding causation. You don’t actually need to know the mechanism to establish causation. It can be done as long as you have properly controlled all confounding factors. More importantly, it is technically never possible to show that X definitely doesn’t cause Y, but what we can do with large studies like the AHS, is show that if X causes Y, it does so at a very, very low rate. That has been established.

Second, regarding the lack of association between non-Hodgkin lymphoma and malathion, both the study I cited and the study on malathion (which I’ll link to below) had to use subsets of the data because obviously not all farmers use the product in question. However, far more used glyphosate than used malathion. As a result, the overall sample size for glyphosate is about twice that of malathion. Further, and more importantly, only around 1,000 of the farmers in the malathion study had cancer of any kind and only 37 non-Hodgkin lymphoma. That’s a very small sample size for detecting an effect in a study of this nature. In contrast, the glyphosate study had nearly 1,500 farmers with cancer in each of their 5 glyphosate use categories (so around 7,500 total), plus over 100 with non-Hodgkin lymphoma in each of the 5 categories. That is a much more robust data set with plenty of statistical power. Further, one of the links you provided also showed that the AHS found evidence of harm from multiple other products.

Regarding the meta-analysis you cited. First, the results are not significant when you look at studies that used oral exposure (which is more relevant for exposure during farming). Studies where the subjects are either injected with glyphosate or soaked in it are hardly applicable to a farm setting (at least if you’re using the product correctly). So when you limit the data to the relevant studies, it actually supports the conclusion that glyphosate is not carcinogenic when used as directed. Additionally, many of the studies used very high doses, so their applicability is limited even when the exposure type is relevant, and animal studies have inherent limitations to begin with. They sit much lower on the hierarchy of evidence than cohort studies. So when a massive cohort study disagrees with a bunch of animal studies, you go with the cohort study (unless there are other issues with the cohort study, obviously). I wrote more about the hierarchy of evidence here https://thelogicofscience.com/2016/01/12/the-hierarchy-of-evidence-is-the-studys-design-robust/

Let me ask you a simple question that will determine whether or not this conversation is worth continuing. What would convince you that glyphosate does not cause cancer in humans when used as directed? I’m stipulating “as directed” because the dose makes the poison and I can easily believe that it is harmful when used incorrectly (resulting in exposure to an excessive dose) because everything is dangerous at a high enough dose. In other words, if a massive cohort study like the AHS isn’t enough to convince you, then what evidence would you find convincing?

Unfortunately, “multiple respected scientific organizations” has no particular website or broadcast time, and neither does the general public have it on speed dial. Neither is a jury verdict any percent irrelevant or without bearing on reality. If you want to know what multiple respected scientific organizations think about the matter at issue, I’d be very surprised if the jury verdict correlated no better than chance–and I bet you haven’t studied that either.

Who, among those who prefer to “leave it to a jury to decide”, would choose a group of 12 of their peers, rather than a trained surgeon, to do their heart transplant procedure? Training and expertise means something, and should be valued.

Let’s don’t forget that everything on this earth can cause harm, even kill you IF not handled correctly. In the case of pesticides according to the label. Salt and aspirin can cause harm and even kill you IF you ingest too much. But almost everyone use salt and aspirin all their lives. Everything we do isa matter of how much risk do you want to take. I choose to take aspirin and use salt on all my food. I also choose to use Roundup but always according to the label just like I do salt and aspirin. In the end it’s my choice and I am not going to blame anyone if I die because of it.

I agree in principle with your main argument. But – not having reviewed the research myself – can you say that it’s had sufficient statistical power to detect a carcinogenic effect at extreme levels of exposure? One of the reviews you cite (Andreotti et al. 2017) actually did find a ~2.5-fold risk for one type of cancer in the highest quartile of agricultural exposure, though it wasn’t statistically significant. In the case of the fellow who won the suit against Monsanto, according to CBS (https://www.cbsnews.com/news/dewayne-johnson-monsanto-roundup-weed-killer-jury-award-today-2018-08-10/):

“… during gusty winds, the product would cover his face, said Brent Wisner, one of his attorneys….He described two days where he ended up accidentally drenched in the herbicide.”

This, despite his testifying that he tried hard to protect himself from exposure. Has the true cancer risk (or absence thereof) for a guy like this, whose exposure level might need to be stratified not into a highest quartile, but into a highest 10% or 1%, be captured by the research so far?

Your question really hinges on what you mean by “extreme levels of exposure.” The lack of significant effect in the highest exposure group int he study I cited does suggest that it is safe even for people who are regularly exposed to high levels of it. Or, to put that another way, if it is carcinogenic, it would take a very, very high level of exposure for it to be carcinogenic, but the problem is that no matter what level we test at, people can always respond with, “well that doesn’t prove that it isn’t carcinogenic at an even higher exposure level.” Do you see what I mean?

Agreed that some people would be motivated to move the goal posts ad infinitum. But my question hinges on two common sense considerations for ascertaining cancer risk without prejudice:

1. Do scientists have a handle on the cumulative exposure level for “drenched” (on occasion, by accident, in the line of occupational duty) or otherwise overexposed workers like the fellow who won the lawsuit?

2. If they do – or can hazard an err-on-the-side-of-caution estimate – is the highest quartile or quintile of exposure sensitive and specific enough to capture that cohort (i.e., without diluting it with people at much lower exposure levels), or would it require deciles or something even finer? If so, has anyone reported such findings? It wouldn’t surprise me if statistical significance is elusive when using such a fine sieve, but it would at least be interesting to see what the trend is – or if there is none.